1. Field of the Invention
This invention relates to an electrical connector, and more particular to a connector with a lever in which connection and disconnection of the connector can be carried out with a small force by the rotation of the lever.
2. Description of the Prior Art
When the number of terminals which are inserted in a connector is increased, a large force is required to connect or disconnect a pair of connectors due to increased contact resistance or force for engagement or disengagement between those connectors, which makes the engagement work difficult.
FIGS. 28 and 29 show the conventional connector with a lever disclosed, for example, in the Japanese Utility model Unexamined Publication No. Showa 52-133993. In this connector, a male connector 100a is provided with levers 100b with supporting pins 100a2 on both sides 100a1 thereof. A female connector 100c is provided on both sides thereof with cam pins 100d which are engaged with cam grooves on the lever 100b. Further, a locking means 100e for the lever 100b is attached to the male connector 100a.
In the first conventional connector described above, at the initial engagement of both connectors 100c and 100b, the cam grooves 100b1 of the levers 100b are engaged with the cam pins 100d and then the levers 100b are rotated in the direction shown by an arrow P of FIG. 28, which permits the male connector 100a to advance into the female connector 100c with a small force due to so-called action of a lever. Then, the engagement of both connectors are completed at the position where the levers 100b are engaged with the locking means 100e as described in FIG. 29.
FIG. 30 shows a second example of the conventional connector with a lever, which is disclosed in the Japanese Utility model Unexamined Publication No. Showa 62-178469. In the figure, a female connector a is provided on both sides with bosses a1 which are inserted into holes b1 for a lever b. Further, locking projections a2 for the lever b and projecting walls a4 are attached to the female connector a. On both sides of a male connector c is provided locking projections c1, which work as a locking means for tip portions b2 of the lever b when both male and female connectors are engaged with each other.
The lever b has a pair of arms b3 of which end portions are connected with a connecting portion b4 and other end portions are bent to form the holes b1 and the tip portions b2. In the connector with a lever having the structure described above, the male connector c is inserted into the female connector a as shown in FIG. 31A. Then, the lever b is rotated clockwise, that is, in the direction as indicated by an arrow P, to urge a locking projection c1 of the male connector c in the direction as shown by an arrow d by the tip portion b2 of the lever b as illustrated in FIG. 31B. The lever b is further rotated to insert the male connector c into the female connector, which permits an arm b3 of the lever b to abut and engage projections a2 at the complete engagement state described in FIG. 31D by way of the state shown in FIG. 31C.
On the other hand, when the connectors are disconnected, the male connector c must be pulled out by hand while the lever b being rotated counterclockwise and the arm b3 of the lever b being stretched outwardly because no action point for the lever b is provided on the male connector c. Therefore, in the above conventional connector with a lever, although the male connector c is inserted in the female connector a with a small force using the rotation of the lever b, only the force by hand can be applied to the male connector c at the disconnection of the connectors. In other words, there is a room for further modification.
In addition, when the connector is used for an automobile or the like, the lever b is held over the female connector before engagement. However, in this state, not only the lever b may be entangled with electrical wires but also it must be held upright until the engagement work is completed, which causes the work to be worrisome.
FIG. 32 is an exploded perspective view of another conventional connector with a lever. In the figure, denoted a' is a female connector and b' a lever, c' a male connector. On both sides a1' of the female connector a' is provided a pair of pin guide grooves a2' and pins a3' to form a locking means with pin holes b2' attached on both sides b1' of the lever b'. On the upper wall a4' of the female connector a' is mounted a resilient locking piece a6' which has a locking projection a5' at the tip thereof. The resilient locking piece a6' and an end b4' of a window b5' provided on a wall b3' composes a locking means.
On both sides b' of the lever b1' is provided cam grooves b8'. A spring b6' has a pair of winding portions, which are inserted in a pair of pins a3'. Further, both ends B10' of the spring b6' abut concave portions a7' which are integrally formed with the pins a3'. Bent portions b11' of the spring b6' abut the lower wall b3' of the lever b'. At the initial stage of the connection, the lever b' is urged so as to be disconnected from the female connector a'.
On the center portion of each of the side walls c1' is fixed a cam pin c2' to form a locking means with the pin guide groove a2' of the female connector and the cam groove b8' of the lever b'.
With the structure of the connector described above, an end of the wall b3' of the lever b' is apart from the female connector a' by the spring b6' and open ends of the cam groove b8' and the pin guide grooves a2' of the female connector a' overlap each other to receive the cam pins c2' of the male connector c'.
Under the condition described above, the male connector c' is inserted into the female connector a' and then the end b9' of the wall b3' of the lever b' is depressed so that the periphery of the cam grooves b8' of the lever b' slides on the cam pins c2' of the male connector c', permitting the male connector c' to move in the direction that it engages with the female connector a'. At the position where the end b9' of the wall b3' of the lever b' is fully depressed, the end b4' of the window b5' is engaged with the locking projection a5' of the resilient locking piece a6' of the upper wall a4' of the female connector a' to complete the engagement of the female connector a' and the male connector c'.
In order to disconnect the female connector a' from the male connector c', the resilient locking piece a6' of the upper wall a4' of the female connector a' is pushed forwardly to disengage the locking projection a5' and the end b5' of the window b4' of the lever b' with each other. However, since it is insufficient for urging force of the spring itself to disconnect the female connector a' from the male connector c', the end b9' of the wall b3' of the lever must be lifted by hand to slide the periphery of the cam groove b8' on the cam pins c2' of the male connector c'. When the open ends of the cam groove b8' and the pin guide groove overlap each other, the male connector c' is pulled out of the female connector a' by hand to complete the disconnection between those connectors.
Therefore, with the conventional connector described above, the spring built-in is separately required, which provides further production cost and assembling work. In addition, it is difficult to carry out the assembling work since the lever b' must be moved from worker's side to the upright position.
FIG. 33 shows third conventional connector, which is a connector with grommet used for an automobile to connect wires between main body side and door side thereof.
The connector with grommet comprises a female connector a" with a grommet a2" having a resilient locking piece a1", which is provided on the door side, and a plurality of male connectors b" to be inserted into the female connector a", which are installed on the main body side.
When the connector with grommet is installed in the automobile, the male connectors b" are inserted into the female connector a" at the main body side as illustrated in FIG. 33 and then the mated connectors are inserted into a panel hole c" from the male connector side so that a flange a3" abuts the periphery of the panel hole c" and resilient locking pieces a1" are engaged with the periphery of the panel hole c".
Therefore, as the number of terminals which are inserted in a connector is increased, a large force is required to connect or disconnect a pair of connectors due to increased contact resistance between those connectors. As a result, a male connector on main body side is required to be divided into a plurality of male connectors to reduce the contact resistance of the male connectors each, resulting in inefficient assembly work. In addition, as another problem, it is difficult to discover incompletely connected connectors.